There's no reason to be ashamed of having ADD - it's an official disorder of the brain that one is born with. You didn't choose it, you didn't ask for it and you didn't bring it on yourself. To
not treat it is foolish. However, one must use discretion when discussing it, that's for sure! I was diagnosed 4 years ago and made the mistake of telling a family member who later, used it against me and belittled me to "taking speed". I never told an employer until just recently and I have benefited from disclosing it. The employer was very understanding and supportive.
That's up to the individual, though. In some cases, it's best to tell the employer, in other cases, it's not. It depends on the work scenario and dynamics of the workplace.
Another possible downside to telling people, is that frankly, they may try to steal your amphetamines if they know you have them! Or they are suddenly "experts" on the field of learning disabilities and psychiatry and bombard you with their opinion.
I have literally hidden my meds when certain people are around or go in the restroom to take my dose so no one was start with the questions. "What is that? Why are you taking it? ADD? Adults aren't ADD! That's just an excuse for laziness!" (Yes, someone actually said that to me!)
So, just remember. Discretion is the better part of valor! Be careful whom you tell. Make sure it's someone that's trustworthy.